title: Running economy during a simulated 60-km trial.
abstract: The effect of a prolonged running trial on the energy cost of running (C(r)) during a 60-km ultramarathon simulation at the pace of a 100-km competition was investigated in 13 men (40.8 ± 5.6 y, 70.7 ± 5.5 kg, 177.5 ± 4.5 cm) and 5 women (40.4 ± 2.3 y, 53.7 ± 4.4 kg, 162.4 ± 4.8 cm) who participated in a 60-km trial consisting of 3 consecutive 20-km laps. Oxygen uptake (VO(2)) at steady state was determined at constant speed before the test and at the end of each lap; stride length (SL) and frequency and contact time were measured at the same time points; serum creatine kinase (S-CPK) was measured before and at the end of the test. C(r) in J · kg(-1) · m(-1), as calculated from VO(2ss) and respiratory-exchange ratio, did not increase with distance. SL significantly decreased with distance. The net increase in S-CPK was linearly related with the percentage increase of C(r) observed during the trial. It is concluded that, in spite of increased S-CPK, this effort was not able to elicit any peripheral or central fatigue or biomechanical adaptation leading to any modification of C(r).
authors.affiliation: Dept of Neurological and Movement Sciences, University of Verona, Verona, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Schena
authors.forename: Barbara
authors.initials: B
authors.lastname: Pellegrini
authors.forename: Cantor
authors.initials: C
authors.lastname: Tarperi
authors.forename: Elisa
authors.initials: E
authors.lastname: Calabria
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Salvagno
authors.forename: Carlo
authors.initials: C
authors.lastname: Capelli
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001696:Biomechanical Phenomena; D003402:Creatine Kinase / Q000097:blood; D004734:Energy Metabolism; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000378:metabolism*; D010101:Oxygen Consumption; D010807:Physical Endurance; D012119:Respiration; D012420:Running; D013997:Time Factors
chemical_list: D015415:Biomarkers; D003402:Creatine Kinase